Steel G20CrNiMo
G20CrNiMo is a nickel-chromium-molybdenum case-hardening bearing steel for large, high-load bearings that need deep case hardness together with core toughness.
Reference datasheet — G20CrNiMo is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the A condition
G20CrNiMo tempers and conditions
G20CrNiMo is supplied in 7 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard GB/T 3203 delivery condition for bearing ring blanks: softest, most uniform structure for turning, boring and cold forming before carburizing. | 400 | 620 | 29 | 190 HB | — |
Normalized | Grain refinement and banding removal on forged rings before carburizing; also used when a tougher machining structure than annealed is wanted. | 430 | 680 | 25 | 14 HRC | 8 % IACS |
Hot rolled | Mill as-rolled bar for forging stock or subsequent heat treatment; hardness too high and non-uniform for finish machining. | 450 | 720 | 22 | 20 HRC | 8 % IACS |
Cold drawn | Small-diameter precision bar for rollers, pins and cages where close tolerance and better surface finish reduce machining allowance. | 620 | 760 | 12 | 22 HRC | 8 % IACS |
Quenched and tempered | Direct-hardened condition for shafts, flanges and non-raceway parts machined from the same bearing-steel stock. | 850 | 1,080 | 14 | 34 HRC | — |
Carburized and hardened | The functional service condition for bearing rings and rollers: hard, compressively stressed deep case on a tough 30–42 HRC core for shock and heavy contact loads. | 950 | 1,250 | 11 | 61 HRC | — |
Carburized, quenched, sub-zero treated and double tempered | Choose when retained austenite must be minimized for precision bearings and long-term dimensional stability at elevated running temperature. | 1,050 | 1,300 | 11 | 62 HRC | 7 % IACS |
What is G20CrNiMo?
G20CrNiMo is a nickel-chromium-molybdenum case-hardening bearing steel for large, high-load bearings that need deep case hardness together with core toughness. Annealed properties are about 400 MPa yield, 620 MPa tensile and 29% elongation at 190 HB, with good machinability (score 60), and stock is supplied as hot-rolled and forged bar, ring blanks and tube for carburizing at 920–940 °C. The steel has no corrosion resistance and needs phosphating, black oxide or an oil film, and service is limited to about 400 °C. G20CrMo is the lower-cost alternative where case depth and core toughness demands are lower. G20CrNiMo has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). G20CrNiMo has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Elongation at break is 29% and the elastic modulus is 210 GPa (30.5 Msi).
What is G20CrNiMo used for?
- Large industrial bearings
- Rail and wind turbine bearings
- Heavy machinery rollers
Advantages
- Polishes to a fine finish — 80/100, better than 97% of steel grades
- Ductile — tolerates forming and impact — 29%, better than 91% of steel grades
G20CrNiMo properties
Typical room-temperature values for G20CrNiMo-A; bars are the position among steel grades.
Physical3
G20CrNiMo has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical14
G20CrNiMo has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Elongation at break is 29% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
G20CrNiMo is rated for continuous service to 400°C (752 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
G20CrNiMo conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of G20CrNiMo takes about 34 MJ of energy and emits 2.3 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability8
G20CrNiMo's machinability is good (60/100, better than 83% of steel grades); weldability fair (50/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. G20CrNiMo is highlighted; hover a dot for its name, or open the interactive family chart.
Working with G20CrNiMo
Is G20CrNiMo easy to machine?
Turn/bore in the annealed ≤229 HB condition with carbide inserts and ample coolant; after carburizing only grinding, honing or CBN hard-turning is practical.
Can G20CrNiMo be welded?
Weldable before carburizing with low-hydrogen consumables, 200–300 °C preheat and post-weld temper; never weld a carburized case.
Can G20CrNiMo be formed, bent or molded?
Hot forge 1100–1180 °C with finish above 900 °C then normalize/anneal; cold forming limited to modest upsetting of annealed stock.
G20CrNiMo chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Clow carbon core for carburizing | 0.17 – 0.23 | 0.2 |
| Si | 0.15 – 0.4 | 0.27 |
| Mn | 0.6 – 0.9 | 0.75 |
| Cr | 0.35 – 0.65 | 0.5 |
| Nicore toughness | 0.4 – 0.7 | 0.55 |
| Mohardenability, temper resistance | 0.15 – 0.3 | 0.22 |
| P | ≤ 0.03 | |
| S | ≤ 0.02 | |
| Cu | ≤ 0.25 | |
| O≤15 ppm total oxygen typical for bearing steel | ≤ 0 | |
| Fe | balance |
What surface finishes work on G20CrNiMo?
Carburize 920–940 °C to the required case depth, quench in oil/press-quench for rings, temper 160–200 °C, then grind and superfinish raceways; protect with phosphating, black oxide or oil film since the steel has no corrosion resistance.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
How much does G20CrNiMo cost?
G20CrNiMo is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
G20CrNiMo — frequently asked
What is G20CrNiMo used for?
G20CrNiMo is typically used for large industrial bearings, rail and wind turbine bearings and heavy machinery rollers. In short: deep-case carburizing bearing steel; tougher core than G20CrMo; sized for large sections.
What is the yield strength of G20CrNiMo?
G20CrNiMo has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is G20CrNiMo easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Turn/bore in the annealed ≤229 HB condition with carbide inserts and ample coolant; after carburizing only grinding, honing or CBN hard-turning is practical.
Can G20CrNiMo be welded?
With care — weldability is rated fair (50/100). Weldable before carburizing with low-hydrogen consumables, 200–300 °C preheat and post-weld temper; never weld a carburized case.
What surface finishes work on G20CrNiMo?
Carburize 920–940 °C to the required case depth, quench in oil/press-quench for rings, temper 160–200 °C, then grind and superfinish raceways; protect with phosphating, black oxide or oil film since the steel has no corrosion resistance.
Can G20CrNiMo be formed, bent or molded?
Hot forge 1100–1180 °C with finish above 900 °C then normalize/anneal; cold forming limited to modest upsetting of annealed stock.
What is the maximum service temperature of G20CrNiMo?
G20CrNiMo is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between G20CrNiMo-A and G20CrNiMo CH-SR?
A is the default condition — standard GB/T 3203 delivery condition for bearing ring blanks: softest, most uniform structure for turning, boring and cold forming before carburizing. CH-SR: choose when retained austenite must be minimized for precision bearings and long-term dimensional stability at elevated running temperature. Yield strength is 400 MPa in A versus 1,050 MPa in CH-SR.
How much does G20CrNiMo cost?
G20CrNiMo is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- GB/T 3203 / (carburizing bearing steel bar) (2016)
- GB/T 3077 (20CrNiMo) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (8620 data) — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing of Ni-Cr-Mo steels) — ASM International (1991)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.